How To Get Ripped Abs

America's top runners have a secret weapon: core training. Steal their moves, and you'll become stronger, fitter, and more efficient on the road.

Every Monday through Saturday at 5 p.m. you can find them, some of the best runners in America--including Meb Keflezighi, Deena Kastor, and Ryan Hall--grunting and groaning together on the carpeted floor of Snowcreek Athletic Club in Mammoth Lakes, California. Under the blare of a techno beat and the watchful eye of coach Terrence Mahon (whom Meb has dubbed "Dr. Pain"), the members of Team Running USA work for 45 minutes toward a common goal: building stronger abs and backs that can only be described in one way--elite.

Intense core training has become essential for elite runners for good reason: It improves efficiency and endurance as it lowers injury risk. Dan Browne, a 2004 Olympic marathoner and a regular carpet-dweller at the 5 p.m. sessions, is quick to cite the benefits he's experienced since beginning a regular regimen: "When I'm running, some of the muscles that used to fatigue don't get tired as quickly, letting me run stronger and longer."

The secret is stability. That's because core strength is the primary force that controls motion in the hips and spine when you run. Think back to when you were learning to ride a bike. You'd wobble and maybe fall until your dad or mom placed a hand on your back. When you run, your core acts as that steadying hand. The stronger the muscles, the more stable your center--and the more efficient your running will be.

A strong core also helps address overuse issues. "If we don't have a strong center, other muscles have to stabilize us," says Toni Dauwalter, a physical therapist whose clients include 2004 Olympic 1500-meter specialist Carrie Tollefson. Over time, the extra work can lead to injury. Mahon cites a litany of problems relating to the lack of that steadying hand: patella tendinitis, piriformis syndrome, sciatica pain.

This is precisely why nearly every top runner busts through some core moves. But there is no industry standard. Routines run the gamut from old-school to cutting-edge. Brian Sell, who finished third in the U.S. Olympic Marathon Trials in November, grunts through 150 sit-ups a day. Tollefson does exercises typical of gym classes: planks and curls. And Shayne Culpepper, a 2004 Olympian at 5000 meters, performs Pilates.

And then there's the routine followed by Team Running USA. In 2006, strength and conditioning coach Dennis Kline of the University of Wisconsin-La Crosse overhauled the squad's ab workout, creating a regimen that targets not just the abdominals but also the back, hips, and glutes (see the exercises in this workout by going here). The program combines static exercises that improve overall strength and muscular endurance with dynamic moves that teach the core and legs to work together. "We're mimicking the running motion," says Kline. "So we use some exercises that engage the core while using the legs."

Josh Cox, who joined the group last July, had never done something so intense on a regular basis. "I was really sore my first week," he admits. Meb, who also initially struggled with some of the exercises, now has impressive strength--and an eye-popping six-pack to prove it. "It's hard work," says Keflezighi, "but in order to be the fastest, you have to be the fittest."